Neurologic Emergencies
Joseph D. Burns, M.D.Attending Neurointensivist
Assistant Professor of Neurology and Neurosurgery
Learning Objectives
• Gain an appreciation for the significant public health burden created by neurologic emergencies
• Understand the diagnostic and treatment considerations unique to emergencies involving diseases of the nervous system
• Be familiar with the differential diagnosis and diagnostic and therapeutic approach to common neurologic emergencies
Why does this matter?
Clinical and Economic Relevance of Neurologic Emergencies
• Stroke– Incidence
• 795,000 new strokes each year in the US• 1 stroke every 40 seconds
– Prevalence• 2.5% of American adults
– Mortality• Third leading cause of death in US• Someone dies of stroke every 3-4 minutes
– Disability• 15-30% permanently disabled• 20% require institutional care at 3 months post-stroke
– Cost• $68.9 billion in the US in 2009• Acute care, long-term care, lost productivity
Lloyd-Jones, Circulation, 2009
Clinical and Economic Relevance of Neurologic Emergencies
• Emergency care burden– 5-15% of all ED visits involve non-traumatic
neurologic problems– 20% of non-surgical admissions are for
neurologic problems
Nawar EW, Advance Data, 2007
What’s different about neurologic emergencies?
Goal 1: Don’t let the patient die
• Not unique
• ACLS, ATLS, other strategies common to all emergency medical care
• Not complicated
Goal 2: preserve as much nervous system tissue as possible
(complicated)
Neurologic Emergencies are Complex
• CNS exquisitely vulnerable to ischemia and hypoxia– Normal CBF: 50-100 mL/100g/min– Ischemia (loss of function): 20 mL/100g/min– Infarction: 10 mL/100g/min
Neurologic Emergencies are Complex
• CNS heals poorly– Tissue that dies is not replaced– Function never returns to normal
Neurologic Emergencies are Complex
• Treatment depends on a rapid, accurate neurologic diagnosis– Requires (unfortunately) unique training and
experience– Attention to detail– As many as 1/3 of patients with Neurology
consultation in ED are misdiagnosed by the requesting physician
Moeller JJ, Can J Neurol Sci, 2008
General Approach
• ABCs– MORE – not less – important– Hypotension and hypoxemia exacerbate CNS
injury– Hypercapnia elevates intracranial pressure
General Approach
• History– ALWAYS the key to diagnosis– Key elements
• Time of symptom onset• Last time seen normal• Temporal profile of symptom onset
– Paroxysmal?– Minutes?– Hours?– Days?
General Approach
• Physical examination: Is there evidence of brainstem dysfunction?– Mental status: level of arousal– Cranial nerves: pupillary responses– Motor:
• Hemiparesis? • Pathologic reflexes? • Pathologic posturing
General Approach
• Imaging: non-contrast CT– Fast– Widely available
• Labs– ALWAYS look for hypoglycemia– CBC, electrolytes, aPTT, PT/INR, LFTs, BUN, Cr
• CSF– Lumbar puncture– CNS infections, subarachnoid hemorrhage, Guillain-
Barre Syndrome
Pearls
• Time is brain
• Successful treatment depends on accurate diagnosis
• Use only normal saline for IV fluids
• Time is brain
Common Neurologic Emergencies
Vignette #1
• 55yo woman with a history of rheumatic heart disease suddenly falls while walking and is unable to move her left limbs
• She has a mechanical mitral valve replacement and stopped warfarin one week ago in preparation for unrelated surgery
Sudden-onset hemiparesis
• Differential diagnosis– Ischemic stroke– Intracerebral hemorrhage– Post-ictal paresis (Todd’s paralysis)
Sudden-onset hemiparesis
• Rapid diagnosis– History
• Time of onset or time last seen normal• Cerebrovascular risk factors• Anticoagulant use• History of seizures
– Exam• Large deficit with preserved arousal: ischemic stroke• Decreased arousal or vomiting: ICH or posterior circulation• Delirium, visual problems, dizziness, cranial nerve
dysfunction: posterior circulation
Sudden-onset hemiparesis
• Rapid diagnosis– Imaging: CT head, CTA head and neck
– Labs: serum glucose, CBC, aPTT, PT/INR
Time is Brain
Saver JL. Stroke. 2006
Time is Brain
Lees KR. Lancet. 2010
Ischemic Stroke Emergent Treatment
• Goal: maximize perfusion to limit infarction– Earlier reperfusion = more salvaged brain = better functional outcome
• Allow hypertension, give IV normal saline, lay head of bed < 30 degrees– Do NOT treat hypertension unless >220/110 mmHg or end-organ
dysfunction• IV tissue plasminogen activator (tPA)
– Within 4.5h of symptom onset– Exclusion criteria extensive (bleeding)
• Endovascular therapy– Contraindications to or failure of IV tPA– Mechanical thrombectomy– Intra-arterial tPA– Within 6h in anterior circulation (ACA, MCA)– Within 12h in posterior circulation (vertebral, basilar)
ICH Emergent Treatment
• Goal– Prevent hematoma expansion
• Occurs in 70% of patients, mostly in 1st 6h• 10% volume increase =
– 5% mortality increase– 16% increase in chance of worsening by 1 point on the modified Rankin
scale– Treat hypertension
• Goal SBP 130-150 mmHg• IV Drugs!!!
– Prns: labetalol, hydralazine– Nicardipine gtt
– Correct coagulopathy FAST!• Goal INR < 1.4, platelets > 100k• PCC, Vitamin K, fresh frozen plasma
Acute hypertension and ICH
• Occurs in 50-75% of patients• Mechanism
– Destruction/interruption of autonomic centers• Prefrontal cortex, insula, hypothalamus
– Increased ICP
• Associated with increased risk of hematoma expansion and poor outcome in a number of retrospective studies
• Chicken or Egg?
Quereshi AI. Circulation. 2008
Acute hypertension and ICH
• Retrospective, single center study from Japan
• Patients– 76 consecutive adult hypertensive ICH
• Outcome– Hematoma growth by ≥ 40%
Ohwaki K et al. Stroke. 2004
Acute hypertension and ICH
• Post-hoc analysis of prospectively collected data on 98 ICH patients– Normal INR– Within 3h of symptom onset
• No relationship between hematoma – SBP– DBP– MAP– Pulse pressure (PP)– PP x HR– MAP x HR
Jauch EC et al. Stroke. 2006
Lower the Blood Pressure
• INERACT (Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial)– Open-label, blinded outcome, randomized, controlled
trial of antihypertensive treatment initiated within 6 hours of ICH onset
– Exclusion criteria• <18yo• SBP <150 or >220• Clear indications for or contraindications against lowering BP
Anderson CS et al. Lancet Neurology. 2008
Vignette #2
• 20yo male college student is found confused and drowsy by his friends on a Sunday morning
• He has a history of epilepsy, is known to be poorly compliant with medications, and was drinking the night before
• 5 minutes after arriving at the ED, he begins to convulse. 3 min into the convulsion, he is not slowing down
Generalized Convulsive Status Epilepticus
• Status epilepticus– Any single seizure lasting > 5min– ≥ 2 seizures without clearing of mental status between them
• Differential diagnosis– Underlying epilepsy with or without AED withdrawal– Drug intoxication (many types) or withdrawal (esp. EtOH and
benzodiazepines)– Hypoglycemia– Vascular disease (infarct, ICH, SAH, AVM)– Electrolyte abnormalities (↓Na, Mg, Ca; ↑Na)– CNS infection– Tumor– Psychogenic, non-epileptic seizure (conversion disorder)
Generalized Convulsive Status Epilepticus
• Rapid diagnosis– History: epilepsy, other neurologic disease,
diabetes, drug ingestion/withdrawal, infectious symptoms, pre-seizure neurologic symptoms
– Exam: • subtle signs of ongoing seizure (periorbital/perioral
clonus, forced horizontal conjugate eye deviation, hippus)
Generalized Convulsive Status Epilepticus
• Rapid diagnosis– Imaging: CT for associated mass lesion– Labs: glucose, electrolytes, urine and serum
toxicology screens– CSF
• Evidence of infection OR• No other clear cause from history, exam, CT, and
labs
Generalized Convulsive Status Epilepticus
• Seizures beget seizures– Early treatment = higher chance of success– Balance this with side effects of treatment
(need for intubation, hypotension)
• Excitotoxic neuronal death
Lactic andrespiratory
acidosis
Lactic andrespiratory
acidosis
Cardiacarrhythmias
Cardiacarrhythmias
RhabdomyolysisRhabdomyolysis
pH
pCO2 Lactate
pH
pCO2 Lactate
AspirationpneumoniaAspirationpneumonia
Pulmonaryedema
Pulmonaryedema
ShoulderdislocationShoulder
dislocationRib
fractureRib
fracture
MyoglobinuriaMyoglobinuria
Status epilepticusStatus epilepticus
CP1142808-43
Figure courtesy of Dr. Eelco F.M. Wijdicks
Emergency Treatment of Generalized Convulsive Status Epilepticus
• Abort the seizure– Lorazepam 4-6mg IV push– Repeat 5min later if seizure continues or returns
• Prevent future seizures– Phenytoin load: 20mg/kg IV infusion– DO NOT just give 1g only enough for a small, 50kg
person– Alternatives:
• IV valproic acid 20-30mg/kg• IV levetiracetam 25-30mg/kg
Vignette #3
• 35yo woman with a history of migraine headaches was awakened by the worst headache of her life and severe nausea. A few minutes later, she vomited.
• ED: BP 170/90. Ill and uncomfortable. Holding an emesis basin, preferred to keep her eyes closed. Slightly drowsy. Resisted passive neck flexion.
Sudden, Severe Headache
• Differential diagnosis– Aneurysmal subarachnoid hemorrhage– Aneurysmal subarachnoid hemorrhage– Aneurysmal subarachnoid hemorrhage– Aneurysmal subarachnoid hemorrhage– Aneurysmal subarachnoid hemorrhage
Sudden, Severe Headache
• Differential diagnosis– Cervical artery dissection– Cerebral venous sinus thrombosis– Intracranial mass– Pituitary apoplexy– Meningitis– Encephalitis– Spontaneous intracranial hypotension
Sudden, Severe Headache
• Rapid diagnosis– History (features of aneurysmal SAH)
• Instantaneous onset of headache• Decrease in arousal/loss of consciousness at
onset• Nausea, vomiting• Family history of aneurysm, SAH• Neck stiffness
Sudden, Severe Headache
• Exam– Meningismus– Retinal subhyaloid hemorrhages (Terson
syndrome)– CN III palsy (ptosis; deviation “down and out”;
pupil fixed and dilated)
Sudden, Severe Headache
• Rapid diagnosis– Imaging
• CT sensitivity declines with time after ictus– Nearly 100% sensitive within 6h– >95% sensitive for SAH within 12h
• CT angiogram: identifies aneurysm– Treatment planning– 20% will have multiple aneurysms
– CSF• LP required if SAH diagnosis is considered and CT negative• 90-95% sensitive for SAH when CT negative• Findings
– Gross blood– Xanthochromia
Emergency Treatment of Aneurysmal SAH
• Notify neurosurgery and neurointerventional team immediately
• Prevent rebleeding – Risk = 5-15% in 1st 24h; mortality 70-80%– Treat hypertension: Keep SBP 110-150 mmHg
• IV Antihypertensives– Prns: labetalol, hydralazine– Nicradipine gtt
• Judicious analgesia– Tylenol Ultram very low-dose IV fentanyl or hydromorphone
– Antifibrinolytics (tranexamic acid) if securing is expected to be delayed > 6h after arrival
Emergency Treatment of Aneurysmal SAH
• Secure aneurysm– Goal: ASAP; within 18h of presentation– Conventional angiogram from ED
• Operative planning• Endovascular coils if possible
– Otherwise, surgical clipping
Vignette #4
• 45yo man with a history of IV heroin abuse presented to the ED with 3 days of worsening headache, confusion, and lethargy
• Exam: Temp 102, BP 100/50, HR 110. Opened eyes to pain only. Uncomfortable, groaning unintelligibly. Meningismus. Systolic murmur
• CSF: RBC 6, WBC 1090 (85% PMNs), glucose 32 (serum 81), protein 234 (nl <70)
• Cultures of blood, urine and CSF all grew MRSA
Fever and Confusion
• Differential diagnosis– Meningitis (bacterial, viral)– Encephalitis (viral)– Cerebral abscess (bacterial, toxoplasma,
fungal)– Subdural empyema– Endocarditis with septic embolic brain infarcts– Non-CNS infection with secondary
encephalopathy
Fever and Confusion
• Rapid diagnosis– History
• Headache, neck stiffness• Oral/nasal infection• Immunosuppression (HIV, chemotherapy,
transplant, diabetes, sickle cell disease, poor nutrition)
• Alcohol abuse• IV drug use• Sick contacts• Travel
Fever and Confusion
• Rapid diagnosis– Exam: meningismus, skin rash, embolic skin lesions,
heart murmur
– Imaging: CT to look for a mass lesion
– CSF (bacterial meningitis)• 10-10,000 WBC/mm3; ≥ 80% neutrophils• Glucose – CSF:serum ratio ≤ 0.5• Elevated protein (> 45 mg/dL)• Check Gram stain and bacterial culture
– Labs: Blood cultures (3 sets), urine culture
Emergent Treatment of Acute Bacterial Meningitis
• Rapid administration of corticosteroids and antibiotics is the key. Within two hours:
1. Blood culture
2. Dexamethasone 10mg IV (20min before ABx)
3. Antibiotics (all IV)• Vancomycin 1.5mg/kg, ceftriaxone 2g• If >50yo or immunosuppressed: add ampicillin 2g
4. CT
5. LP
Vignette #6
• 45yo man presented to the ED complaining of back pain, generalized weakness, and shortness of breath
• Illness began 5d ago when he awoke with tingling in the feet. Later that day, his walking became clumsy. Cold 3 weeks ago
• Exam: Afebrile. RR 35, diaphoretic, anxious. Bifacial weakness and mild dysarthria. Symmetric weakness of proximal limbs. Muscle stretch reflexes diffusely absent.
Vignette #6 (cont)
• Intubated in ED
• LP: Protein 100mg/dL (normal < 70); RBC, WBC, glucose normal.
Weakness and Difficulty Breathing
• Differential diagnosis– Guillain-Barre syndrome– Myasthenic crisis– Cervical cord lesion– Severe myopathy– Sepsis
Weakness and Difficulty Breathing
• Rapid diagnosis– History
• GBS: gait unsteadiness, distal limb paresthesias, proximal weakness, cramping, back pain
• Myasthenic crisis: history of MG, prominent CN involvement (diplopia, “nasal” voice, dysphagia, nasal regurgitation) fatigability
– Exam• GBS: diffuse hyporeflexia or areflexia• MG: prominent CN symptoms; fluctuation of
symptoms
Figure courtesy of Dr. Eelco F.M. Wijdicks
Weakness and Difficulty Breathing
• Rapid diagnosis– Imaging: consider MRI of cervical spine if
CNs are spared– CSF
• GBS: elevated protein with up to 10 WBC (“albuminocytologic dissociation”)
– Labs: arterial blood gas
Emergency Treatment of GBS and Myasthenic Crisis
• Goal: Control breathing before catastrophe
• Intubation and mechanical ventilation– Airway compromise from CN dysfunction– Even if O2 and CO2 are OK
• Vital capacity < 15mL/kg• Negative inspiratory force worse than -30 cm H2O• Rapidly worsening respiratory function
– Do not wait for ABG results
Emergency Treatment of GBS and Myasthenic Crisis
• GBS– Intravenous pooled human immunoglobulin
(IVIg)– Plasma exchange
• Myasthenic Crisis– Plasma exchange more rapid improvement– IVIg only if plasma exchange contraindicated
Take-Home Messages
• Time is brain
• Rapid diagnosis and treatment are crucial
• ABCs are important in neurologic illness
• Ischemic stroke: don’t lower BP and open the vessel
• ICH: lower BP and correct coagulopathy
• SAH: lower BP (carefully) and secure aneurysm
Take-Home Messages
• Meningitis: give steroids, then antibiotics, as soon as the diagnosis is considered… before the LP
• MG crisis/GBS: respiratory failure is sneaky – intubate before the ABG
• Never sedate a patient with critical neurologic illness unless the neurointensivist or neurosurgeon says it’s OK
• Never give any IV solution other than Normal Saline unless the neurointensivist or neurosurgeon says it’s OK
• Time is brain
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